Description
A lightened-up version of the classic green bean casserole that combines fresh green beans with caramelized onions, cremini mushrooms, and a creamy Parmesan sauce, topped with seasoned whole wheat panko breadcrumbs for a healthier, flavorful side dish perfect for holiday dinners or weeknight meals.
Ingredients
Units
Scale
Vegetables
- 2 pounds fresh trimmed green beans, snapped in half
- 1 large sweet onion, very thinly sliced
- 16 ounces cremini mushrooms, chopped
- 3 garlic cloves, minced or pressed
Fats and Oils
- 1 tablespoon olive oil
- 2 tablespoons unsalted butter
Liquids
- 1 1/4 cups low-sodium chicken stock
- 1 cup low-fat half and half
Dry Ingredients
- 2 tablespoons flour
- 1/2 cup whole wheat panko bread crumbs
- 1 teaspoon salt, divided
- 1/2 teaspoon pepper
- 1/4 teaspoon thyme
- 1/4 teaspoon oregano
- 1/4 teaspoon freshly grated nutmeg
Cheese
- 2 tablespoons freshly grated parmigiano reggiano cheese, divided
Instructions
- Preheat the Oven: Preheat your oven to 400 degrees Fahrenheit to prepare for baking the casserole.
- Caramelize Onions: Heat a large oven-safe skillet over low heat and add olive oil, sliced onions, and 1/4 teaspoon salt. Stir well to coat, cover, and cook the onions for about 20 minutes, stirring occasionally, until they turn a caramel color and become sweet and tender.
- Prepare Green Beans: While the onions cook, bring a large pot of water to a boil. Add the green beans and cook for 5 minutes until slightly tender but still crisp. Drain and rinse under cold water, then let them air dry in the sink until ready to use.
- Mix Seasoned Panko: In a small bowl, combine the whole wheat panko breadcrumbs with thyme and oregano. Set this mixture aside for topping later.
- Cook Mushrooms and Garlic: Remove caramelized onions from the skillet and place them in a bowl. To the same skillet, add butter and chopped mushrooms, tossing to coat. Cook mushrooms for 6 to 8 minutes until soft and releasing juices. Add half of the caramelized onions and the minced garlic, cooking for an additional 30 seconds.
- Make the Sauce: Increase skillet heat to medium-high, sprinkle the flour evenly over the mushroom mixture, and stir well to coat. Cook for 2 to 3 minutes to eliminate raw flour taste. Gradually pour in the chicken stock and half and half while stirring constantly. Allow the sauce to bubble and cook for 2 to 3 minutes until it thickens slightly but remains pourable.
- Season and Combine: Season the sauce with the remaining salt, pepper, and freshly grated nutmeg. Stir in 1 tablespoon of the grated parmigiano reggiano cheese. Add the blanched green beans to the skillet and toss everything together to coat evenly with the sauce.
- Assemble the Casserole: Evenly cover the green bean mixture with the remaining caramelized onions, then sprinkle the seasoned panko mixture and the remaining tablespoon of parmigiano cheese on top.
- Bake: Place the skillet in the preheated oven and bake for 25 minutes until the casserole is bubbly and the breadcrumb topping is golden brown and crisp.
- Serve: Remove from oven and serve immediately for the best texture and flavor.
Notes
- For a vegetarian version, substitute chicken stock with vegetable stock.
- Make sure not to overcook the green beans when boiling; they should stay crisp to maintain texture after baking.
- Use an oven-safe skillet to avoid transferring the mixture to another baking dish.
- Caramelizing the onions slowly over low heat develops the deep, sweet flavor essential to this casserole.
- If you prefer a crunchier topping, broil the casserole for 1-2 minutes at the end of baking, watching closely to prevent burning.
